Anaerobic Co Digestion of Poultry Manure and Waste Kitchen Oil

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<ul><li><p>7/29/2019 Anaerobic Co Digestion of Poultry Manure and Waste Kitchen Oil</p><p> 1/9</p><p>Slovak Society of Chemical Engineering</p><p>Institute of Chemical and Environmental Engineering</p><p>Slovak University of Technology in Bratislava</p><p>PROCEEDINGS37th International Conference of Slovak Society of Chemical Engineering</p><p>Hotel Hutnk</p><p>Tatransk Matliare, SlovakiaMay 24 28, 2010</p><p>Editor: J. Marko</p><p>ISBN 978-80-227-3290-1</p><p>Lazor, M., Hutnan, M., Sedlcek, S., Kolesrov, N., palkov, V.: Anaerobic co-digestion of poultrymanure and waste kitchen oil, Editor: Marko, J., In Proceedings of the 37th International Conference ofSlovak Society of Chemical Engineering, Tatransk Matliare, Slovakia, 13991406, 2010.</p></li><li><p>7/29/2019 Anaerobic Co Digestion of Poultry Manure and Waste Kitchen Oil</p><p> 2/9</p><p>Anaerobic co-digestion of poultry manure and waste kitchen oil</p><p>Lazor, M., Hutan, M., Sedlek, S., Kolesrov, N., palkov, V.</p><p>Institute of Chemical and Environmental Engineering, Faculty of Chemical and Food</p><p>Technology, Slovak University of Technology, Radlinskho 9, 812 37 Bratislava, SlovakRepublic</p><p>Keywords: poultry manure, waste kitchen oil, biogas, co-digestion</p><p>1.0 Introduction</p><p>Agro food industry is a huge producent of wastes that can be for energetic purposes used.Excrements of animals as poultry, swines, livestocks are one of them. Their energetic contentis still sufficient for composting or anaerobic digestion. Annual animal excrement productionin Slovak Republic is about 13 700 000 t what can be used for 1,03 TWhe(3,7.10</p><p>15 J) electricenergy and 2,8 PJt (2,8.10</p><p>15 J) heat energy production. For this aim 258 biogas stations areneeded.</p><p>Tab.1Basic technologic parametres for different animal excrements anaerobic digestion [1]Parameter Dimension Swine Beef Poultry</p><p>Minimal digestiontime</p><p>d 13 17 16 21 25 30</p><p>Temperature0C 38 42 38 42 38 42</p><p>Maximal loading of</p><p>biosludgekg VS/m</p><p>3/d 5 4 3</p><p>Biogas production m3/kg VS/d 0,35 0,20 0,40</p><p>Very perspective method of agro food wastes utilization is co-digestion, where differentbiodegradable wastes are together anaerobic treated. At choice of treated wastes many factorstake into account is needed. The most important are price and access of wastes, theircomposition (organic mass and mineral content), methane yield from organic mass, price ofneeded digestion technology etc. Co-digestion has in comparison with single anaerobicfermentation several advantages.</p><p> increased biogas production with single fermentation of wastes comparison</p><p> minimal green house gases producing disposition of wastes, which occupy large planes contaminations restraint of ground waters destruction of pathogenous germs in raw waste smell removal digested waste is perfect bio-organic fertilizer</p><p>In this presented work poultry manure as a animal waste and waste kitchen oil as a restaurantwaste were chosen. Poultry manure was chosen due to its biggest methane yield related to 1kg volatile solids (VS) (Tab.1) and waste kitchen oil due to its high energetic content (Tab.3).This experiment is only part of big study where intensification methods to anaerobic process</p><p>are aplicated.</p><p>37th International Conference of SSCHE</p><p>May 2428, 2010, Tatranske Matliare, Slovakia Po-Th-6, 113p.pdf </p><p>1399</p></li><li><p>7/29/2019 Anaerobic Co Digestion of Poultry Manure and Waste Kitchen Oil</p><p> 3/9</p><p>2.0 Experimental</p><p>Aim of this work was monitoring of biogas production and its composition from agro-foodwastes. The first of all, anaerobic digestion of poultry manure and wasted kitchen oil wasinvestigated. Organic fraction ratio of poultry manure and wasted oil in this presented work</p><p>was 9:1.. Temperature value of this anaerobic process was maintaining in mesophilic scalei.e. 37oC. As an anaerobic laboratory apparatus, semicontinuous reactor was used. Substratesfeeding and excess sludge removal was every day and biosludge loading by volatile solidswas inceasing gradually untill fermentation colaps . Periodically biogas composition by themobile IR spectrophotometer was measured. As an anaerobic stabilized inoculum wastewater sludge was used. Average input substrates parameters, resp. inoculum like COD,ammonia concentration,pHand organic fraction (OF) is in table2.</p><p>Tab 2. Basic parameters of inocculum stabilized waste water anaerobic sludge</p><p>COD [mg/l] 1370</p><p>NH4+</p><p>[mg/l] 231VFA [mg/l] 369</p><p>Xc [g/l] 7,5</p><p>pH 7,8</p><p>Pic.1 1-isolated laboratory reactor, 2-stirrer with electromotor, 3-time switch, 4-electric heating withregulation, 5-drum gas gauge, 6-feeding open</p><p>Total reactor volume was approximately 17 l, where anaerobic mixture occupied 15 l.Therefore, remaining space about 2 l as an improvised gasholder serviented. From there,excess gas through the bubbler to flow-meter was led away. Mixing of anaerobic mixture bypropeller blender was secured. Process temperature was measured by thermometer, which themixtures heating was regulating.</p><p>6</p><p>4 3</p><p>1</p><p>2</p><p>5</p><p>37th International Conference of SSCHE</p><p>May 2428, 2010, Tatranske Matliare, Slovakia Po-Th-6, 113p.pdf </p><p>1400</p></li><li><p>7/29/2019 Anaerobic Co Digestion of Poultry Manure and Waste Kitchen Oil</p><p> 4/9</p><p>3. Results and discussions</p><p>3.1. Poultry manure waste kitchen oil anaerobic digestion</p><p>Aim of this experiment was monitoring biogas production and its composition at graduated</p><p>organic mass loading and also measuring of processing parameters that characterize anaerobicprocesses (pH, NH4+, VFA (volatile fat acids), Xc (dry mass content)). For anaerobic systems</p><p>these parameters are indical and change one of them cause change the other. Experiment wasrunning until system began be collapsing. Poultry manure and waste kitchen oil as a co-fermentation system was chosen.Co-digestion started with initial organic mass (VS) loading on the level 0.3 kg VS/m3/d andgradually was increased until final value 1.2 kg VS/m3/d. Feeding by manure and oil was atevery loading to constant VS ratio both substrates , it means 9:1. First 12 days organic massloading was 0.3 kg VS/m3/d, 13 23. day 0.5 VS/m3/d, 24 120. day 0.7 VS/m3/d, 121 143. day 1 VS/m3/d and finally 144 305 day 1.2 VS/m3/d. In generally anaerobic systemstabilization is long time process that take several weeks till months. It depends on many</p><p>factors ( intensity of organic mass loading, temperature and composition of input substrates).</p><p>Fig.1 Anaerobic process parameters time development (COD, VFA, NH4+)</p><p>Organic mass loading is mostly expressed two ways loading by volatile solids (VS) andloading by COD. Because different substrates has different organic mass composition, itmeans different COD related to 1 kg VS , better and for anaerobic processes more valuableparameter COD should be. Typical example studied co-digestion system poultry manure waste kitchen oil was. Chemical oxygen demand (COD) for poultry manure was 0.9 gCOD/kg VS, eventually 2340 COD/kg VS for waste kitchen oil (Tab. 3).Poultry manure was periodically taken from near farm and subsequently stored in fridge.Waste kitchen oil was taken from university canteen and also stored in fridge. Average storedtime for poultry manure was 2 3 weeks. If stored time overreached 3 weeks, manure starteddecompose. It was indicated by ammonia smell. If so particularly decomposed manure wasdosing, always unstability in anaerobic process was happened. As can be shown in Fig.1,every dosing of particularly decompose manure caused increasing COD, NH4</p><p>+ and VFA.</p><p>After 125th</p><p>co-digestion days stored time of manure was decreasing to 10 days. As a resultwas stabilizing of anaerobic process.</p><p>0,0</p><p>2 000,0</p><p>4 000,0</p><p>6 000,0</p><p>8 000,0</p><p>10 000,0</p><p>12 000,0</p><p>14 000,0</p><p>16 000,0</p><p>18 000,0</p><p>0 50 100 150 200 250 300</p><p>COD [mg/]</p><p>VF A [mg/l]</p><p>NH4+ [mg/l]</p><p>time[ d ]</p><p>37th International Conference of SSCHE</p><p>May 2428, 2010, Tatranske Matliare, Slovakia Po-Th-6, 113p.pdf </p><p>1401</p></li><li><p>7/29/2019 Anaerobic Co Digestion of Poultry Manure and Waste Kitchen Oil</p><p> 5/9</p><p>Tab.3 Organic mass and COD biosludge loading through the anaerobic digestion poultry manure -waste kitchen oilTotal organic mass</p><p>loading[kg VS/m</p><p>3/d]</p><p>Organic massloading - manure</p><p>[kg VS/m3/d]</p><p>Organic massloading - oil[kg VS/m</p><p>3/d]</p><p>COD loading - manure[g COD/m</p><p>3/d]</p><p>COD loading - oil[g COD/m</p><p>3/d]</p><p>0,3 0,27 0,03 0,243 70,2</p><p>0,5 0,45 0,05 0,405 117</p><p>0,7 0,63 0,07 0,567 163,8</p><p>1 0,9 0,1 0,81 234</p><p>1,2 1,08 0,12 0,972 280,8</p><p>COD - manure 0,9 g COD/kg VS</p><p>COD - oil 2340 g COD/kg VS</p><p>Optimal pH value for anaerobic process is in interval 6.5 7.5. For holding this valueexistence of acid basic buffer system is needed. In anaerobic system co-exist two basicbuffer system (ammoniac NH3 + H</p><p>+ NH4+ and carbonate CO3</p><p>2- + H+HCO3- ). However</p><p>if substrate with high total nitrogen content is digested (poultry manure), inhibition ofanaerobic processes can happen. For example if swine manure is digested, upper limit freeammonia value is 1,1 g NH3 N/l. Ammonia is generated from nitrogenous matters asproteins and urea [3].Free ammonia and NH4</p><p>+ are two main inorganic nitrogenous forms inaqueous solutions. Free ammonia toxicity is caused its freely membrane-permeability andconsequently causing proton imbalance or potassium deficiency [4]. From all anaerobic typesof microorganisms, the methanogens are the least tolerant and the most likely to cease growthdue to ammonia inhibition [5]. There are many different maximum free ammoniaconcentrations for methanogens on literatures. For example , as ammonia concentrations wereincreased in the range of 40515734 mg NH3N/l, acidogenic populations in the granularsludge were hardly affected while the methanogenic population lost 56.5% of its activity [6].</p><p>In our present work , after 175th</p><p>digestion day free ammonia inhibition started be significant,if concentration 4000 mg NH4+/l was overreached (Fig.1). According [11] free ammonia if</p><p>concentration of NH4+ is known can be counted as follows: pH = (TAN/(1+10(pKa pH)).</p><p>In 175th day pH = 8,4, pKa = 8,95 [11] a therefore concentration of free ammonia NH3 = 1130mg/l.</p><p>Fig.2 pH development during anaerobic digestion of poultry manure waste kitchen oil</p><p>7,4</p><p>7,6</p><p>7,8</p><p>8</p><p>8,2</p><p>8,4</p><p>8,6</p><p>8,8</p><p>0 50 100 150 200 250 300 350</p><p>time[ d ]</p><p>pH</p><p>37th International Conference of SSCHE</p><p>May 2428, 2010, Tatranske Matliare, Slovakia Po-Th-6, 113p.pdf </p><p>1402</p></li><li><p>7/29/2019 Anaerobic Co Digestion of Poultry Manure and Waste Kitchen Oil</p><p> 6/9</p><p>During treatment of waste containing high concentrations of TAN (total ammonia nitrogen),pH affects the growth of microorganisms as well as the composition of TAN [7]. Processinstability due to ammonia often results in volatile fatty acids (VFA) accumulation, whichagain leads to a decrease in pH and thereby declining concentration of free ammonia FA. Theinteraction between FA, VFAs and pH may lead to an inhibited steady state, a condition</p><p>where the process is running stably but with a lower methane yield [8]. In our presented workthis situation occurred after 175th co-digestion day, where pH value due to free ammoniastarted increase (Fig.2) and consequential rise of COD and VFA concentration (Fig.1).</p><p>Fig.3 Biogas production related to 1 kg added VS</p><p>This free ammonia inhibition caused decrease of biogas production (Fig.3). System waspseudo stable, it means that biogas production was stabilized and oscillated between 200 300 m</p><p>3/kg VS/d. However in comparison with biogas production before inhibition (before</p><p>175th day , 400 - 600 m3/kg VS/d) it was only 50 % yield (Fig.3). Toxic influent of freeammonia caused also decrease in methane content in biogas (Tab.4). Therefore the mostimportant if substrates with high nitrogenous matters are anaerobic digested (poultry manure)is decrease of free ammonia concentration. There are two main physicalchemical methodsto free ammonia removal, air stripping and chemical precipitation [9]. For ammoniaprecipitation magnesium ammonium phosphate can be used. Another posibility is dilution ofmanure to a total solid level of 0.53.0% . This approach is joined with economicunattractivity due to high waste volume [10].Various types of inhibition can be counteracted by increasing the biomass retention in thereactor. It was found that the methane yield in a CSTR could be increased by switching offthe stirrer half an hour before and after substrate addition [11]. Ammonia inhibition can bereduced using different types of inert material (clay, activated carbon, zeolite) or adding ofionic exchanger or adsorbants (natural zeolite, glauconite) [12]. Another parameter that canaffects to free ammonia concentration temperature is. As is known , higher temperature haspositive impact to microorganisms growth and metabolic rate, on the other side highertemperature leads to higher free ammonia concentration, thus to inhibition. Several authorshave found that anaerobic treatment of waste with high ammonia is less stable in thermophilicconditions in comparison with mesophilic digestion [13]. It was discovered that some ions as</p><p>Na+</p><p>, K+</p><p>, Ca2+</p><p>and K+</p><p>have anti inhibition effects, mainly joined with free ammoniainhibition.</p><p>0,00</p><p>200,00</p><p>400,00</p><p>600,00</p><p>800,00</p><p>1000,00</p><p>1200,00</p><p>0 50 100 150 200 250 300 350</p><p>time [ d ]</p><p>Biogas production [m3/ kg VS/ d]</p><p>37th International Conference of SSCHE</p><p>May 2428, 2010, Tatranske Matliare, Slovakia Po-Th-6, 113p.pdf </p><p>1403</p></li><li><p>7/29/2019 Anaerobic Co Digestion of Poultry Manure and Waste Kitchen Oil</p><p> 7/9</p><p>Tab.4 Biogas composition (poultry manure waste kitchen oil)Digestion</p><p>day14 22 34 41 57 71 83 91 111 127 147 165 187 210 235 251 270 294</p><p>Organic</p><p>mass</p><p>loading [kg</p><p>VS/m3/d]</p><p>0,3 0,5 0,7 0,7 0,7 0,7 0,7 0,7 0,7 1 1,2 1,2 1,2 1,2 1,2 1,2 1,2 1,2</p><p>componets Biogas composition</p><p>CH4</p><p>[%]60,4 56,6 53,9 45,2 70,7 58,8 55,8 57,8 56,2 55,5 52,3 51,4 52,4 50,3 49,8 50,1 46,4 48,3</p><p>CO2</p><p>[%]33,3 36,8 40,1 48,7 24,4 33 38,9 37,1 37,5 37,6 40,1 41,6 43,1 45,3 44,3 42,3 47,3 45,9</p><p>O2</p><p>[%]1,1 1,4 1,3 1,6 0,9 1,2 1 1 1,1 1 0,9 1,1 1,2 1,1 1 0,9 1,1 1,2</p><p>H2S</p><p>[ppm] 104 137 740 1210 515 169 806 455 1069 1152 1005 1054 1003 989 1052 1035 989 1105</p><p>H2</p><p>[ppm]165 42 55 51 85 100 80 80 68 80 95 101 125 114 131 145 167 195</p><p>4.0 Conclusions</p><p>1. Co - digestion of poultry manure and waste kitchen oil was occurred. Initialorganic mass loading was 0,3 kg VS/m3/d and consequently gradually increasedup to 1,2 VS/m3/d. Organic mass ratio between poultry manure and waste kitchen</p><p>oil was during all co-digestion on constant level 9:1.</p><p>2. It was found that high concentration of free ammonia has very negative influenceto anaerobic process and for co-digestion of poultry manure waste kitchen oilupper limit concentration of free ammonia on level 1130 mg NH3/l was detected.</p><p>3. Free ammonia inhibition caused decrease in biogas production, where from originproduction before inhibition (up to 175th co-digestion day) 400 600 m3/kg VS/ddeclined to 200 300m3/kg VS/d (after 175th co-digestion day)</p><p>4. It was discovered, that if storage time of poultry manure is very long (2 weeks and</p><p>longer), its decomposition happened to ammonia production. It led to highconcentration of ammonia in dosing batch and subsequently to inhibition ofanaerobic process.</p><p>5. The most important if substrates with high nitrogen content are digested is reduceconcentration of free ammo...</p></li></ul>

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